Heavy industrial equipment such as dump trucks, tractors and the like commonly employ dual wheel assemblies. Typically, these assemblies include two rims mounted on a common axis having a pair of pneumatic tires, one mounted on each rim. A spacing is provided between the opposing walls of the pneumatic tire casing. Foreign objects such as rocks and the like can become lodged in the spacing formed between the pneumatic tire casings. This often leads to irreparable damage to the tire casings. A number of devices have been employed to either free or prevent foreign objects from becoming lodged in the space between the pneumatic tire casings of a dual wheel assembly. A common method used to free objects is to suspend a steel bar from the underside of the frame of the vehicle which protrudes in the space between the two
Case 5942 tires. If a rock is driven over and becomes lodged between this space it will rotate with the tires until such time as it strikes the steel bar. However, there are numerous disadvantages to this system. For instance, if a rock becomes severely lodged between the pneumatic tire casings, the act of dislodging it by the steel bar can in and of itself lacerate one or both of the tire casings. Also, small rocks can become lodged between one tire casing and the steel bar. Once again the tire casing will be exposed to undesirable forces which will likely damage the same.
It has also been proposed to provide large metallic plate shaped members in the space between the pneumatic tire casings. See for example U.S. Pat. No. 2,397,741. However, this arrangement is also unsatisfactory. When a large solid object is run over by a truck, forklift or other heavy industrial equipment, the weight of the vehicle can apply such a force to the object that it in turn bends the plate shaped objects into the pneumatic tire casings. This will not only damage the tires but will likely render the vehicle inoperative.